There will be at least one slap of Marshall's remaining slaps against Barney.

However, executive producer Carter Bays is still keeping his mouth mum about the exact details of the slap. He says, "There’s a little bit of a twist on the slap this year. The Slap Bet commissioner makes an interesting ruling that I can’t reveal."

We will give you a hint. Marshall gives away his slap and it will be used by one of the other How I Met Your Mother cast members... or Lily's father. Watch their potential slaps in action: